Cutting back/pruning lilac
 

I would appreciate the advice of the learned folk here please.
We have 2 lilac trees (Syringa, I think) in very close proximity. One bears
white blooms, the other purple.
You may have guessed that I am a beginner.
These were planted by my mother 40-50 years ago. A few years later my father
planted some leylandii immediately to the south of the lilacs to provide a
screen.
Neither the lilacs nor the leylandii have seen any attention in many a year.
The leylandii grew to 12m+, put the lilacs in permanent shade and demolished
the garden wall.
The lilacs slowly reached out for light (I am presuming) until the main
stems/trunks were about 30 degrees above horizontal and were only supported
by the remains of the garden wall. If upright they would be 5-6 metres
For reasons I won't go into here I have not been able to give this much
attention since my father passed away 5 years ago.
For the last 4 years I have jacked up, and propped, the trunks of the lilacs
a few inches every winter. They are now at about 40 degrees.
Severe winds and prevailing conditions have caused the leylandii to
'disappear' over the last few weeks and the lilacs will now be able to have
the benefit of full sunlight.
It is lovely to see these once again. Also I can rebuild the wall and
reinstall a gate.
I have googled for advice which ranges from prune in autumn to prune in
spring immediately after flowering to cut it down at ground level.

Light and better conditions are now available to the lilacs.
If I take some of the weight out of the crowns are they ever likely to do
well or succeed?
I really don't want to cut them down. My wife and I enjoy both the plants
and the blooms but there is also some sentimentality on my part.

Thank you,
Nick.

Cutting back/pruning lilac
 

No expert either, but i took over an overgrown lilac, and just pruned it
back really hard one autumn.
Its grown remarkably, didnt flower that spring, so guess it flowers on new
growth, now I just prune when
the flowes die

Lilacs are very difficult to kill, even when growing through a leylandii hedge. (He says, from the bitter experience of the neighbour's lilac invading my garden through the neighbour's leylandii hedge.) Generally speaking, you can hack them back hard as you like, when you like. So long as you omit to use a suitable weedkiller, they'll come back.

The Leylandii, on the other hand... The trouble with letting them get overgrown is that you can't substantially reduce their fatness, because if you trim them back beyond the green, because they won't regrow from the brown. But the really good thing about leylandii is if you prune them at ground level with a single horizontal cut, they won't ever grow again! Isn't that nice?

Cutting back/pruning lilac
 

Nick writes


Light and better conditions are now available to the lilacs.
If I take some of the weight out of the crowns are they ever likely to do
well or succeed?
I really don't want to cut them down. My wife and I enjoy both the plants
and the blooms but there is also some sentimentality on my part.

If they were mine, I would cut back the almost horizontal 'trunk' by
about half, leaving any branches that are growing near the 'base'. That
would encourage more new shoots from the 'base', which, now the
leylandii are gone, would tend to grow vertically. They would start
flowering in about 3 or 4 years. Once the new growth is really
established (2-3 years time), you can cut the horizontal stuff back more
and more.

Even though lilac is tough, I don't like cutting back anything too
severely because there's always a slight chance it won't recover. So I'd
look to be pruning and re-shaping over about 3 years (with other shrubs,
an accepted technique is to cut about a third of the branches right down
to the base each year).

If you do do the job gently over a few years, you can always keep a
straggly branch or two to make sure you have some flowers each year.

Don't overdo things, and let the plants teach you how to go about it.

This heavy pruning can be done over the winter (not when frosty) while
the tree is dormant.

After-flowering pruning in the spring is light tidying up of a tree that
is already in good shape. Doing it in spring allows the whole summer
for regrowth and formation of flower buds - you won't get any flowers
the following year on branches that have only had the
autumn/winter/spring to grow in.
--
Kay

Cutting back/pruning lilac
 

"K" wrote after
Nick asked (snip)

Light and better conditions are now available to the lilacs.
If I take some of the weight out of the crowns are they ever likely to do
well or succeed?
I really don't want to cut them down. My wife and I enjoy both the plants
and the blooms but there is also some sentimentality on my part.

If they were mine, I would cut back the almost horizontal 'trunk' by about
half, leaving any branches that are growing near the 'base'. That would
encourage more new shoots from the 'base', which, now the leylandii are
gone, would tend to grow vertically. They would start flowering in about 3
or 4 years. Once the new growth is really established (2-3 years time),
you can cut the horizontal stuff back more and more.

Even though lilac is tough, I don't like cutting back anything too
severely because there's always a slight chance it won't recover. So I'd
look to be pruning and re-shaping over about 3 years (with other shrubs,
an accepted technique is to cut about a third of the branches right down
to the base each year).

If you do do the job gently over a few years, you can always keep a
straggly branch or two to make sure you have some flowers each year.

Don't overdo things, and let the plants teach you how to go about it.

This heavy pruning can be done over the winter (not when frosty) while the
tree is dormant.

After-flowering pruning in the spring is light tidying up of a tree that
is already in good shape. Doing it in spring allows the whole summer for
regrowth and formation of flower buds - you won't get any flowers the
following year on branches that have only had the autumn/winter/spring to
grow in.

A few years ago, whilst helping some new neighbours to reclaim their garden,
we found a large Lilac tree that had fallen right over with most of the
large trunk rotten (subsequently found it was a home for Stag Beatle
larvae). I pruned it with a chain saw right back to the original trunk/root
system leaving just a few new growths that had sprouted on that part of the
plant. Whilst it didn't flower for a couple of years it's now a very healthy
large multi stemmed flowering shrub.

When back to how you want it keep it there with hard pruning after
flowering. Prune at another time and you will lose the flowers for next
season.

--
Regards
Bob Hobden

Cutting back/pruning lilac
 

The message
from "Nick" contains these words:

Light and better conditions are now available to the lilacs.
If I take some of the weight out of the crowns are they ever likely to do
well or succeed?
I really don't want to cut them down. My wife and I enjoy both the plants
and the blooms but there is also some sentimentality on my part.

You can cut them right down if necessary and they will regrow from the
roots. They are almost sure to sucker anyway.

You can prune to your heart's content, they will come back again, even
if it's only to spite you...

--
Rusty
Direct reply to: horrid dot squeak snailything zetnet point co period uk
Separator in search of a sig

Cutting back/pruning lilac
 

"Rusty_Hinge" wrote in message
k...
The message
from "Nick" contains these words:

Light and better conditions are now available to the lilacs.
If I take some of the weight out of the crowns are they ever likely to do
well or succeed?
I really don't want to cut them down. My wife and I enjoy both the plants
and the blooms but there is also some sentimentality on my part.

You can cut them right down if necessary and they will regrow from the
roots. They are almost sure to sucker anyway.

You can prune to your heart's content, they will come back again, even
if it's only to spite you...

--
My sincere thanks to all for the encouraging, thoughtful and helpful
replies.
I have some decisions to make but I now have some knowledge to base any
decision on.
I liked the comment about cutting leylandii back at ground level with a
single horizontal cut.
Brought a chuckle to my wizened old vizog.
I took no pleasure in 'cutting back' the leylandii, just the wrong plants in
the wrong place and utterly out of control.
On a plus note, I plant about 80 trees every year. Mainly oak, beech, walnut
and ash.
Have done so for the last 5 years and will continue to do so whilst I am
able.

Thanks again,

Nick.